Contact jaw



J. G. J'ACKSON Feb. 7', 1939.

CONTACT JAW Original Filed Nov. 30,

' INVENTOR. Jafir; 6f J'dr/ka arf.

ATTORNEY.

Patented Feb. 7, 1939 John G. Jackson, Detroit, Mich assignor to Square D Company, Detroit, Mich., a corporation of Michigan original'appiication November 30, 1934, Serial- Divided and this application July 1, 1935, Serial No. 29,278

8 Claims. (01. 200-166) v This invention relates to electric switches and more particularly to an electrical contact particularly adapted for electrical switches.

This application is a division of my copend- 5 ing application, Serial No. 755,265, filed'November 30, 1934.

One object of this invention is to provide an improved contact jaw.

Another object of this invention is to provide 10 a switch contact jaw having increased rigidity and provided with improved supporting means.

Another object of this invention is to provide an improved contact jaw in which the supporting means is secured to the free end of one of 15 the legs of the jaw and in which the free end of the other leg is provided with an extension to form an arcing tip.

Another object of this invention is to provide an improved construction for a contact jaw rea sulting in increased strength and rigidity.

Another object of this invention is to provide an electric switch including an improved contact .jaw arrangement.

Further objects and features of the invention 2 will be apparent to those skilled in the art from the following specification and; the appended drawing illustrating certain preferred embodimentsof the invention in which: Figure 1 is a front elevational view of a switching device according to the present invention with the cover open.

Figure 21s an enlarged sectional view taken on line IIII of Figure 1.

Figure 3 is a perspective view of one form of a contact jaw according to present invention.

Figure 4 is a perspective view of a modified form of contact jaw.

Referring tothe drawing, the electric switch therein shown is more particularly described and claimed in the aforesaid copending application. It embod es a box or cabinet, i having a cover 2 hingedly mounted on one side thereof. 0n the same side of the cabinet adjacent the front edge thereof there is hingedly mounted a sup- 4| porting plate or strap 3 in a position to be spaced from the rear wall of the cabinet. The free end of the supporting strap extends adjacent to the opposite side of the cabinet and has a stud 4 threaded therein. An operating handle 5 has an operating bar. extension 6 which extends through openings in the opposite sides of the supporting strap and is pivotally mounted therein. The side.

of the cabinet adjacent to the free end of the strap is provided with a slot which receives the 1 3 operating handle I and stud 4 in the enclosed po'siton of the switch. The stud 4 when tightened down serves to secure the supporting plate in its enclosed position.

. An insulating base i is mounted on brackets 8 at the top and bottom of the supporting plate 5 -and extending forwardly thereof. At either side of the base and substantially centrally thereof are mounted hinge jaws 9 and H of substantially the same form as the contact jaw members to be hereinafter described. The hinge jaws 10 have movable contact blades I2 and I3 pivoted therein. Arcuate insulating members It and I5 are rigidly secured to the movable contact blades and have slotted ends, not shown, which, engage the operating bar 6. Adjacent to the top of they insulating base and at either side thereof are mounted contact jaws i8 and IS in position to receive the ends of contact blades i2 and I3. Each contact jaw (Figure 3) comprises parallel faces 2| and 22 having diverging portions at their lower ends joined by a flat portion 23. A supporting and connecting plate 24 is formed as a flange at the free end of' contact face 22, while the free end of contact face 2! has a flared extension 25 forming an arcing and guiding tip. 25 The supporting plate 24 has a threaded opening centrally thereof and raised portions 26 on its upper surface which serve as'conductor retaining means or as means to prevent rotation of a fuse clip mounted on the plate. The plate 24 is 30 mounted on the front of the base i and is se-' cured thereto by stud 21 which extends through and beyond the plate and has a nut 28 thereon for the purpose of clamping an electrical conductor against the front surface of plate 24. 5 The diverging portion of contact face 22 has a finger 29 cut therefrom and bent into the space between the faces to limit the movement of the contact blade. The hinge jaws 9 and ii may be of the same form but having aligned apertures 40 for pivoting the contact blades and with the flared tip 25 omitted. 1

The contact arrangement described above is particularly adapted for use-where the height above the insulating base is limited and is, therefor, particularly adapted for, although not limited to, use with the switching device of the type herein described where a switch unit is mounted forwardly of the rear wall of the enclosing cabinet.

The hinge jaws 9 and Ii are, each connected in a well known manner to one terminal of fuse sockets 3i and 32, the other terminals of whichare provided with accessible conductor receiving means 33 and 34.

The arrangement of the switch upon the pivoted saddle 3 permits swinging of the entire interior out of the box when the stud 4 is loosened, thus facilitating the adjusting of conduit to the box and the drawing in of wires. When the wires have been brought into the box the mounting plate 3 and the switch mounted thereon can then be swung back into the cabinet and secured in that position by the stud 4.

The switch jaw described above and particularly shown in Figure 3 provides a very convenient means for connection to a base block where the height is limited and for electrical connection to the jaw through the plate 24. The flared extension 25 provides an arcing tip to prevent burning away of the support for the contact jaw. The diverging portions at the ends of the faces 2| and 22 assist in maintaining a true parallelism between the faces and impart rigidity tothe jaw.

A modified form of contact jaw is shown in Figure 4. This is similar to that shown in Figure 3 with the exception of the joining portion.

In this modification the ends of the jaw faces 2!.

and 22 are joined by a portion 35 which is provided with a curvature in a plane parallel to the contact faces. In other words, the portion 35 not only constitutes a curve joining the faces 2| and 22 but is curved intermediate the edges of the faces so that its bottom portion is bowed or curved downwardly intermediate the edges. This curvature greatly increases the strength and rigidity of theparallel contact faces of the jaw and serves to increase the contact pressure as well as, to retain the faces in their desired parallel position,

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited ing and connecting means therefor including a strap integrally connected to and extending at right angles from the free end of one of said members, and a flared extension on the free end of the other of said members extending upwardly and outwardly to form a guiding and arcing tip.

3. A contact member comprising a generally U-shaped jaw, a supporting strap connected to the free end of one of the legs of the jaw and having an aperture therein for engagement with a securing stud, conductor retaining means on the surface of said strap and spaced from saidv aperture, the other leg of the jaw flaring upwardly and outwardly above said free end to provide an arcing tip.

4. A switch contact comprising parallel jaw members and a connecting portion, said connecting portion being curved in a plane parallel to the jaw members.

5. A contact comprising parallel jaw members and a connecting portion, said connecting portion being curved in a plane parallel to the jaw members, and supporting and connecting means for said jaw members comprising a supporting strap connected to the free end of one of said members.

6. A contact comprising parallel jaw members and a connecting portion, said connecting portion being curved in a plane parallel tothe jaw members, and supporting and connecting means for said jaw members comprising a flange extending at a right angle adjacent to the free end of one of said members, and a flared extension on the free end of the other of said members providing a guiding and arcing tip.

7. A contact comprising parallel jaw members, diverging portions at the lower ends of the jaw members, a hat portion joining the diverging ends, and supporting and connecting means for said jaw members comprising a flange extending JOmI G. JACKSON. 

